Blood vessels

Question 1

Components?

Answer 1

55% plasma, 45% blood cells and platelets

Question 2

Erythrocytes?

Answer 2

a nucleate, have a lifespan of 100-120 days, biconcave, 7x2 micrometers

Question 3

Production of erythrocytes

Answer 3

erythropoiesis: prenatally in yolk sac and spleen and liver, postnatally in marrow cavity of bones such as ribs, vertebrae. Leave bone marrow and synthesise Hb , 3 days later they lose all their RER

Question 4

2 types of leukocytes

Answer 4

Agranulocytes: lymphocytes, monocytes
Granulocytes: neutrophils, basophils, monocytes

Question 5

Two types of blood vessel

Answer 5

Pulmonary - low pressure

Systematic - high pressure

Question 6

Elastic fibres use

Answer 6

smooth out pulsatile flow

Question 7

General 3 coat structure

Answer 7

Intima = inner layer, smooth, simple squamous, endothelium
Media = layer is large in arteries yet thinner in veins, smooth muscle that maintains blood pressure
Adventitia = outer, connective tissue, external elastic layer, vast vasorum

Question 8

Phases og Haemostasis? (stopping blood loss)

Answer 8

1. contraction of smooth muscle so vasoconstriction
2. platlets agregate
3. Fibrin network over plug 30 sec after injury
4. clot dissolved by fibrinolysis